Matthew McGregor, who was appointed on Friday, said that hitting people with more than £10million in assets with the levy would be 'a highly popular way' of raising £24billion for the Treasury.

The PM-in-waiting has said he is 'not going to rule things out' when it comes to hiking taxes for the wealthiest in society

Steve Rotheram, the Liverpool City Region Mayor has given the strongest hint yet that the incoming prime minister is considering introducing the levy